Apparatus for closing packaging containers with elastically deformable walls

ABSTRACT

Apparatus and method for automatically closing heat-sealable, liquid-filled, flexible-walled containers by means of a cover which is heat sealed to the container. Prior to sealing, container wall portions are depressed by push rolls to decrease the cubic volume of the container during the automatic heatsealing step.

United States Patent [56] References Cited UNITED STATES PATENTS l/l967 Loddingmumu.

[72] Inventor Adoltvogel Matstadt Wurth, Germany 812,526

21 Appl. No. 22 Filed 3,342,009 9/1967 Andersonm,

3,4l8,l93 12/1968 Hallowell 3,457,694 7/1969 Tatibana Primary Examiner-Theron E. Condon Assistant Examiner-Robert L. Spruill Attorney-Edward E. Sachs [32] Priority [54] APPARATUS FOR CLOSING PACKAGING CONTAINERS WITH ELASTICALLY DEFORMABLE WALLS 4 Claims, 2 Drawing Figs.

ABSTRACT: Apparatus and method for automatically closing 53/329, heat-sealable, liquid-filled, flexible-walled containers by 53/39, 53/373 means of a cover which is heat sealed to the container. Prior to [51] Int. B65b 7/28 sealing, container wall portions are depressed by push rolls to [50] Field ot 53/24, 39, decrease the cubic volume of the container during the automatic heat-sealing step.

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ATTORNEY APPARATUS FOR ILOSINGPACKAGINGCONTAINERS WITH ELASTICALLY DEFORMABLE WALLS I I This invention relates generally to automatie,'high-speed, packaging machinery and more particularly, to an apparatus for. the closing of ,packaging containers composed of heat sealable material in which a coveris placed upon and heat sealed to the container rim. 1 a 1 Experience with prior art devices has shown that in the process of closing containers filled with liquids, discontinuities are frequently established in the closing seam. These leakcausing breaks usually occur due to the heat which is generated during the heat-sealing step within the container which causes not only the air in the enclosure to be heated, but also causes part of the liquid within the region of the closing seam to be vaporized, so that due to the combination of these factors excess pressure is generated in the package which frequently has the tendency to partly open the soft seam before the seam has solidified and hardened.

The problem thus posed by the prior'art was to prevent an increase in pressure during heat sealing of the cover.

in accordance with this invention, it is suggested to deform wall portions of the container prior to the heat-seal step to decrease the cubic volume of the container and to terminate the force, which causes the deformation, not earlier than during the heat-seal step.

The apparatus proposed in accordance with this invention prevents the building up of any excess pressure in the packaging container. Moreover, when the predetermined degree of momentary wall deformation selected is greater than the pressure required to establish pressure equalization, an additional advantage is achieved in that the cover, due to the outside air pressure, is still forced against the edges of the packaging container while the seal jaws have already been turned away.

One other considerable advantage of the new apparatus arises from the fact that during deformation of the packaging container, the level of the liquid rises, so that at the preceding transport, from the fill station to the closing station, the level of the liquid can still be held sufficiently remote from the edge of the packaging container to avoid overflow. Due to the subsequent rise of the container contents level, the hollow area in the head of the container is nevertheless so considerably decreased that the package finally has only a small content of oxygen. This reduction of oxygen has a beneficial effect upon a great many goods in that it furthers the maintenance of quality.

An aspect of the present invention resides in the provision of an apparatus for closing liquid-filled, flexible-walled containers, each with a cover which is heat sealed to the container. The-apparatus includes a heat-sealing station, a con veyor: device for transporting the filled containers to the heatsealing station, a container wall deforming arrangement located close to the sealing station and effective for changing located cubic volume of the container in response to actuation of the deforming mechanism and, finally, a drive connected to the deforming device and effective to momentarily force the deformer against the flexible wall of the container to temporarily reduce the volume thereof.

it is therefore the primary object of this invention to provide an apparatus for closing a container to which a cover is heat sealed, without a break in the heat-sealed seam zone.

For a better understanding of the present invention, together with other and further objects thereof, reference is had to the following description taken in connection with the accompanying drawings, and its scope will be pointed out in the appended claims.

In the drawing:

FIG. 1 is a fragmentary side view of the apparatus; and,

FIG. 2 is a fragmentary top view of the apparatus according to FIG. 1.

Turning now to the drawing, the apparatus is essentially comprised of a plurality of conventional heat seal devices 1,

carrying radially open conveyor cups 3 which-continuously rotate with the wheel, and a pair of guide. rails 4, 5 disposed along the rotating path of the cups 3 to guide the bottom and the outside of the packaging containers 6. The apparatus further includes several push-in 'rolls 7 which are arranged proximateto the main heat-seal station S and are movable towardand against the open side of the conveyor cups 3, each carrying a container 6.

In the preferred.embodiment three push-in rolls 7 are provided and mounted on lengthwise adjustable arms 8 which form a rotating star D. The rolls, or container deforming members, rotate around a common vertical axis 9, by means of conventional driving mechanism, in such a manner, that the speed of rotation of rolls 7 is essentially the same as the conveyor speed for cups 3. The driving means may, for example, comprise chain wheels 11 and 12, a drive chain 13 and gears 14 and 15. The chain wheel 11 is secured to a drive shaft 16 which serves to rotate conveyor wheel 2. The chain wheel 12 is driven by drive chain 11 by way of connecting chain 13 and the wheel effects rotation of gear 15 due to engagement with gear 14. The gear 15 drives the rotating star D about axis 9. The total transmission ratio of wheels 1.], 12, 14 and 15 corresponds to the number of conveyor cups 3 provided on conveyor wheel 2 divided by the number of push-in rolls 7 on rotating star D.

During the rotation of conveyor wheel 2, one conveyor cup 3 and push-in roll 7, at a time, advance toward the heat-seal station S, in such a manner, that the out-er wall of the packaging container 6 in cup 3 is elastically depressed to a predetermined degree. The selection of the degree or extent of depression is dependent upon the desired decrease of the volume of the packaging container 6. The push-in rolls are barrellike and are rotatably mounted to a bolt 10 secured to arms 9. Should the desired decrease in the volume not be attainable in the case of, for example, a packaging container 6 having a square cross section, and taking into consideration all of the abovementioned points, solely by depressing one of the four packaging walls, it is of course possible to provide and arrange for the depression of another wall, for instance the opposite one, to accomplish the desired objective.

The deformation or depression of the container wall is maintained, at least in part, concurrently with the heat-sealing step. In other words, the forces exerted by the engagement of rolls 7 against containers 6 are withdrawn not earlier than during the heat-sealing process.

The pressing of the seal seam by means of conventional press jaws (not shown), provided in the heat seal arrangement 1, is suitably initiated when the temporary depression of the packaging container 6 has reached its upper limit. When reaching the desired extent of depression of the packaging container 6, there occurs, as already noted, after the push-in rolls have been turned away, a slight underpressure in the containers which effects that during the cooling of the closing seam the cover rim is also pressured against the container rim.

The arrangement of push-in rolls 7, in accordance with this invention, is also feasible when the rolls, as well as the cups 3, are driven stepwise and the cups are, for instance, secured to an endless conveyor chain.

A further embodiment of the apparatus may include one or more push-in rolls 7 guided against the stepwise movable conveyor cups 3, carrying packaging containers 6, by means of steering or straight guides.

While there have been described what are at present considered to be the preferred embodiments of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is aimed, therefore, in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What l claim is:

1. In an apparatus for closing filled, flexible-walled containers each with a cover and heat sealing the same thereto;

a heat-seal station;

container-deforming means are arranged on rotating means having a speed of rotation conforming to the speed of said conveyor means to effect that the deforming means engage, in sequence, a container.

3. Apparatus according to claim 2,'wherein said rotating means forms a star having lengthwise adjustable arms.

4. Apparatus according to claim 3, wherein said deforming means are barrellike rolls, each rotatably mounted to one of said arms. 

1. In an apparatus for closing filled, flexible-walled containers each with a cover and heat sealing the same thereto; a heat-seal station; conveyor means for transporting filled containers to said heatseal station; container deforming means located proximate to said station and effective for varying the cubic volume of said container in response to actuation of the deforming means; and driving means connected to said deforming means and effective to temporarily force the deforming means against the flexible wall of the container to temporarily reduce the volume thereof.
 2. Apparatus according to claim 1, wherein a plurality of container-deforming means are arranged on rotating means having a speed of rotation conforming to the speed of said conveyor means to effect that the deforming means engage, in sequence, a container.
 3. Apparatus according to claim 2, wherein said rotating means forms a star having lengthwise adjustable arms.
 4. Apparatus according to claim 3, wherein said deforming means are barrellike rolls, each rotatably mounted to one of said arms. 